重金属Cu对两种海洋微藻的毒性效应

Toxicity effects of heavy metal copper on two marine microalgae

研究了重金属Cu对两种海洋微藻中肋骨条藻和三角褐指藻的生长以及藻细胞超氧化物歧化酶(SOD)、过氧化物酶(POD)和丙二醛(MDA)含量的影响。结果表明,较高浓度的Cu2+对中肋骨条藻和三角褐指藻的生长都产生了明显的抑制作用,72hEC50分别约为(0.546±0.068)和(0.531±0.037)mg/L。对两种海洋微藻的SOD和POD活力的影响,均表现为低浓度诱导,高浓度抑制,MDA含量则随着Cu2+浓度的提高逐渐上升。在72hEC50浓度分别对相应藻种的胁迫下,SOD和POD活力表现为前期诱导后期抑制,MDA含量则随着胁迫时间的延长逐渐升高。两种海洋微藻的SOD、POD活力和MDA含量的改变与添加的Cu2+浓度具一定的相关性,因此可以考虑作为监测重金属Cu污染的有价值的生物标志物。

The effects of heavy metal copper on the growth, superoxide dismutase （SOD） and peroxidase （POD） activities, malondialdehyde （ MDA ） content of marine algae Skeletonema costatum and Phaeodactylum triconutum were studied. The results showed that the higher Cu^2＋ concentration inhibited the growth of both of the algae, and the 72h ECso were about （0. 546 0. 068） mg/L for S. costatum and （0. 531 0. 037） mg/L for P. triconutum. Within 0 - 1. 262 mg/L, the activities of SOD and POD of two algae were increased in lower Cu^2 ＋ concentration group comparing with that in the control, while decreased in higher Cu^2 ＋ concentration group. The MDA content was increased gradually with the increasing Cu^2 ＋ concentration. For the two algae, the SOD and POD activities were increased at earlier exposure, and then decreased at later exposure at the Cu^2＋ concentration of individual 72h ECso exposure, while the content of MDA was increased with the prolonged exposed time. The results showed that both of SOD and POD activities, MDA content of marine microalgae are related with Cu^2 ＋ concentration in the medium, therefore, they could be as referenced biomarkers of Cu^2＋ stress.